Don't get me wrong, the until now series 9 has finally got a pretty good episode, and the odd wry humour and sometimes scary moments make it standard quality of Doctor Who overall. The fairly good acting and nice effects help the good story and the outright beautiful set pieces. While its suffers the odd drop in tension, under the lake is (finally) a return to good Doctor Who thoroughfare. My main flaw with this episode is the laughable excess of references to the Alien movies (particularly 2 and 3). One character is a blatant rip-off of the Weyland-Yutani executive Burke from Aliens, and one scene almost feels like a parody of the 'bait and chase' scene from Alien3. This doesn't make the episode 'bad' at all, but how can I take the episode seriously if it won't take itself seriously. OK, i'm being harsh here. Under the lake has a beautiful setting (Bioshock) and good acting, but the next part needs less references to popular movies. That was what Red Dwarf was for. 7/10 - Good